ive got a different engine (D4F 1.2 16v) but you will be able to do simmilar on your engine.
the airbox on mine had a seperate chamber so it still held air but kept the engine quiet, probably helps with fuel economy etc so i cut that out so its all 1 big chamber..
now the airflow was improved which made a noticeable difference combined with my HKS panel filter (which i also custom made) but the standard cold air feed seemed a bit narrow and restrictive so i replaced that with a slightly wider one...
the members who have heard my car will tell you themselfs that its twice as loud as any induction kit you can get for the engine, infact sounds like its got a stealth exhaust on it when its got the standard system! sounds mental and goes better than other 1.2 16vs too!